Tire building drum



May 30, 1933.

.INVENTOR M ILL/HI'I E. SW51? BY v ATTORNEYS Patented May 30, 1933UNITED STATES PATENT OFFICE WILLIAM E. SWERN, OF KOKOMO, INDIANA,ASSIGNOR, BY MESNE ASSIGNMENTS, TO

' PAUL A. FRANK, OF AKRON, OHIO TIRE BUILDING DRUM Original applicationfiled August 23, 1926, Serial No. 130,883, now Patent No. 1,754,583.Divided and application filed Kay 20, 1929, Serial No. 364,378, nowPatent No. 1,854,813. Divided and this application filed May 5, 1931.

The present invention relates to the manufacture of pneumatic tirecasings or carcasses, and the invention is particularly adapted anduseful in the so-called flat building or drum methods of manufacture. v

In the manufacture of tires by the flat band method as practiced priorto my invention, a transversely flat drum has been used which is capableof being slightly expanded. The inner plies of the carcass are appliedto the drum, then the beads are slipped in place thereon and the drum isexpanded tightly against the inner peripheries of the beads. The underplies are folded over the beads and then the outer plies are placed overthe carcass, over the beads and over the turned-up edges of the underplies and around the beads. When these tires are later expanded in theiruncured state to horseshoe shape in section and vulcanized, it isnecessary that the bead portions of the tire rotate or twist excessivelyin reaching their final positions in the finished tire. The excessivetwisting of the bead portions of the carcass sets up stresses in thecarcass adjacent the bead and causes considerable shifting ordisplacement of the edges of the plies which cause breaking down of thecarcass above the beads when the tires are in service.

In certain types of bead constructions, the bead reinforcement used maytwist or rotate upon itself, but other types of reinforcement are notcapable of any internal twisting or shifting. In any event thedistortion or displacement and twisting of the bead reinforcements andthe edges of the fabric plies constituting the carcass is undesirableand may lead to early failures of the tire, but by the use ofthe presentinvention these objections are reduced to a minimum and it is possibleto build tires by the flat band method in .a satisfactory manner,without sacrificing any of the benefits accruing from that method ofbuilding.

It has also been suggested to provide a drum with head seats formed byreduced portions at the edges of the drum, the side faces of whichsubstantially converge toward the center of the drum whereby beadsmolded and semi-cured to their final shape Serial No. 535,140.

may be molded in a flat band tire. This form of bead is incapable of anytwisting and the process is necessarily limited for this reason. Thistype of drum, however, requires the ad-. ditional step of expensivestitching of the inner fabric plies about the converging faces of thebead seats and the important advantage of the flat band method ofuniform stretching of the carcass to tire-shape as a whole is notpresent.

The object of the invention is. to provide a form or drum for thebuilding of a tire in which the central or body portion of the drum andthe tire built thereon is flat or cylindrical, being provided with dropsides or reduced seats for the location of the beads or bead cores whichform the beaded edges of the casings. These seats should notsubstantially converge and in fact may be inclined outwardly or divergeas shown in the accompanying drawing. This drop side constructionpermits the positioning of beads in the formation of a flat drum carcassbelow the cylindrical periphery of the carcass. It also permits usingflat wire tape bead constructions and when the tire is later expanded toshape the bead portion of the carcass is not required to twist or rotateexcessively, the shifting of the edge of the plies is reduced to aminimum, and this type of bead can accommodate itself to the amount oftwisting which is required. By the apparatus shown and described herein,it is possible to build tires by the flat band method and use the wirebead type of reinforcement without the disadvantages of the priorsystems and with distinct advantages as is well known to those skilledin this art. Any form of head reinforcement may be used with thebuilding drum shown herein, and the results are highly beneficial in thecommercial man-.

ufacture of automobile tires of the straight side variety. For example,the placement of beads against the fabric of the under fabric plies onthe sides or reduced shoulders of the drum eliminates loose fabricformat-ions about the beads such as result from attempting to set thebeads on the periphery of a flat drum. It will be seen that due toclearance necessary to pass the bead over the inner plies onto theperiphery of a fiat drum the fabric plies inwardly of the bead are notcompressed into snug engagement with the bead when the beads are set.Also with this drum the under plies are more easily turned up about thebead and the over plies are more easil turned down under the' bead sincethe plyorming tools are easily insertable under the beads on the sidesor reduced shoulders of the drum. Further it will be noted that byreason of the crown portion of the drum being greater than the beaddiameter the fabric of the flipper and breaker strips is not stretchedor expanded so much as with the tire built entirely flat.. These stripsare not shaped so much as they are expanded when a tire is shaped andare likely to be execs sively strained by expansion of a tire builtentirely fiat. A further advantage of the use of this drum is that bymaking the crown diameter of the drum in certain proportions Withrespect to the rim diameter of the finished tire for the various sizesof tires, fabric cut 'on the bias using the same cutting angle may beemployed for various sizes of tires and will produce tires when expandedand vulcanized in which the angles of the cords are approximately thesame. This dispenses with frequent ad ustment of fabric bias cutters toproduce runs of stocks cut upon the bias at different angles. Thus inproviding drums in accordance with this invention of different sizes forthe different sizes of tires to be made the crown diameters of the drumsmay be increased with respect to the rim diameters whereby the sameinitial bias cutting angle may be maintained for all fabric plies.

This invention is a division from my copending application Serial No.36t,378, filed May 20, 1929, which is in turn a division of myapplication Serial No. 130,883, filed August 23, 1926, now Patent No.1,7 54,583, dated April 15, 1930, which latter as stated therein is acontinuation in part of my application Serial No. 723,353, filed June30, 1924, now Patent No. 1,741,208, dated December 31, 1929.

The full nature of the invention will be understood from theaccompanying drawing and the following description and claims Of theaccompanying drawing,

Figure l is a front elevational view of a sin le unit drum;

igure 2 is a side elevational view thereof;

Figure 3 is an enlarged central sectional view of a portion of tirecarcass and the supporting drum showing the parts in expanded position,the dotted llnes showing the parts in the telescoped or collapsedposition for carcass removal, the tire illustrated being of the clinchertype; and

Figures 4 and 5 are enlarged central sectional views of a portion of amodified drum with the carcass positioned thereon, the former figureillustrating a drum adapted for clincher type tires and the latter adrum for tending upwardly therefrom is a supporting standard 13.Projecting laterally from said standard is a support 14 for a drumspindle 15 mounting the drum 16. A suitable clutch is associated withthe spindle and the drum is rotated through power means controlled by alink 18 and terminating in the foot lever 19. Lock 17 holds the shaftstationary for telescoping the drum through parts not shown so that theparts of the drum may be telescoped when the drum is rotated either byhand or by momentum previously acquired through shaft rotation.

The drum may consist of a pair of annular members 60 provided with aperipheral face 61 recessed to receive a cylindrical member 62, the saidcylindrical members being telescopically associated. In this way anywidth of drum surface can be obtained for any given diameter of bead. Ofcourse different diameter drums may be substituted so that the samemachine, by interchanging drums, is capable of forming carcasses for acomplete line of tire sizes.

Each of the circular members 60 includes face 63, and in the drawingsthese faces are shown oppositely inclined to each other and beingrelieved or tapered as at 64. The drum is suitably supported upon thespindle l5 and is rotated thereby. The inclined face 63 and relievedportions 64 permit the bead 65 0f the tire to lie substantially belowthe main body portion thereof when formed on the drum. This constitutesthe drop side formation of the tire carcass. The resultant adjustabledrum construction permits any width of tire to be obtained for any givenbead diameter and, as shown in the drawing, said tire may be of eitherthe straight side or clincher type, Figures 3 and 4 illustrating theclincher type and Figure 5 the straight side type.

Figures 4 and 5 show substantially the same drum, the first beingadapted for forming clincher type tires and the second for straight sidetires. These drums difler from those shown in Figure 3 by having arelieved face 264. The same parts are indicated by numerals of the 200series, 262 indicating the tubular portions telescopically associatedtogether, 260 indicating the frame members and 263 the inclined face.

In the manufacture of thesetires the inner carcass plies may be foldedor formed down onto the bead seats and the bead portion thereof is builtin such position that rotation or twisting of the bead portion of thecarcass occurs in passing from the fiat built condition to the shape ofa tire casing.

By the construction of the drum shown herein the beads are seated inaxially offset 'tral portion of the casing.

drum and the carcass plies are easily formed .over these seats.

To remove the carcass of the tire from the drum the two sections of thedrum are brought together, decreasing the overall width of the drum tosuch an extent that the tire may be removed by swinging one side of thetire over the collapsed drum, while the other side of the drum is forcedinto the cen- After the tire is removed from the drum, it is brought totire form by bringing the edges together and expanding the centralportion of the tire. The beads which are employed will twistsufliciently without injurio'usly affecting the plies of building fabricadjacent thereto. The tire is then vulcanized in the usual manner.

Modifications of the invention may be,

resorted to without departing from the spirit thereof or the scope ofthe appended claims.

What is claimed is 1. A machine for building drum type tires of thecharacter described, comprising a drum including a cylindrical tire bodysupporting surface, and an annular face extending inwardly from each ofthe edges thereof and inclined outwardly from each other for supportingthe beads substantially flush with the tire body, said inclined beadsupporting surfaces being unobstructed laterally to per-,

mit the placement of circular beads said surfaces.

2. A machine for building drum type tires of the character described,comprising a dim including a cylindrical tire body supporting surface,and an annular face extending inwardly from each of the edges thereofand inclined outwardly from each other for supporting the beadssubstantially flush with the tire body, each of the inclined annularfaces being provided with an annular oppositely directed extension andunobstructed to permit sidewise placement of a circular bead.

3. A machinefor building drum type tires of the character described,comprising a drum including-a cylindrical tire body supporting surface,and an annular face extending inwardly from each of the edges thereofand inclined outwardly from each other for supporting the beadssubstantially flush with the tire body, each of the inclined annularfaces being provided with an annular oppositely directed extension, saidextensions being inclined toward the axis.

4. A tire building drum having a substan tially cylindrical peripherywith substantially non-converging faces at the sides thereof onto whichthe margins of inner tire carcass plies may be formed, said facesproviding seats against which the preformed, circular beads of the tiremay be set on said inner carcass plies.

against 5. A tire building drum having a substantially cylindricalperiphery with diverging faces at the sides thereof onto which themargins of inner tire carcass plies may be formed, said faces providingseats against.

which the preformed, circular beads of the tire may be set on said innercarcass plies.

6. A drum for building tires by the flat band method, said drum having asubstantially cylindrical building surface, and lat erally unobstructedand reduced bead seats on opposite sides thereof, the bead seats be ingso located that the beads are set in an angular position different fromthat occupied in the finished tire whereb the beads are required totwist in the su equent formation of the tire preparatory tovulcanization.

7. A drum for building tires by the flat band method, said drum having asubstantially cylindrical peripheral portion with faces at the sidesthereof on which circular beads maybe seated within the outer peripheryof the cylinder, said faces being unobstructed and so located as toposition the beads in laterally ofi'set relation to said cylindricalportion.

8. A drum for building tires' by the flat band method, said drum havinga substantially cylindrical portion with reduced, .unobstructed beadseats at the sides thereof, said seats being adapted to positionpreformed, circular beads in laterally offset relation to saidcylindrical portion, said drum having surfaces connecting said beadseats with the peripheral cylindrical portion.

WILLIAM E. SWERN.

